Commit 0eead9ab authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Don't dump task struct in a.out core-dumps 



akiphie points out that a.out core-dumps have that odd task struct
dumping that was never used and was never really a good idea (it goes
back into the mists of history, probably the original core-dumping
code).  Just remove it.

Also do the access_ok() check on dump_write().  It probably doesn't
matter (since normal filesystems all seem to do it anyway), but he
points out that it's normally done by the VFS layer, so ...

[ I suspect that we should possibly do "vfs_write()" instead of
  calling ->write directly.  That also does the whole fsnotify and write
  statistics thing, which may or may not be a good idea. ]

And just to be anal, do this all for the x86-64 32-bit a.out emulation
code too, even though it's not enabled (and won't currently even
compile)

Reported-by: default avatarakiphie <akiphie@lavabit.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 53eeb64e

arch/x86/ia32/ia32_aout.c

+5 −17
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ 
#include <asm/ia32.h>



#undef WARN_OLD

#undef CORE_DUMP /* probably broken */

#undef CORE_DUMP /* definitely broken */



static int load_aout_binary(struct linux_binprm *, struct pt_regs *regs);

static int load_aout_library(struct file *);
@@ -131,21 +131,15 @@ static void set_brk(unsigned long start, unsigned long end) 
 * macros to write out all the necessary info.

 */



static int dump_write(struct file *file, const void *addr, int nr)

{

	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;

}

#include <linux/coredump.h>



#define DUMP_WRITE(addr, nr)			     \

	if (!dump_write(file, (void *)(addr), (nr))) \

		goto end_coredump;



#define DUMP_SEEK(offset)		\

	if (file->f_op->llseek) {					\

		if (file->f_op->llseek(file, (offset), 0) != (offset))	\

			goto end_coredump;				\

	} else								\

		file->f_pos = (offset)

	if (!dump_seek(file, offset))	\

		goto end_coredump;



#define START_DATA()	(u.u_tsize << PAGE_SHIFT)

#define START_STACK(u)	(u.start_stack)
@@ -217,12 +211,6 @@ static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, 
		dump_size = dump.u_ssize << PAGE_SHIFT;

		DUMP_WRITE(dump_start, dump_size);

	}

	/*

	 * Finally dump the task struct.  Not be used by gdb, but

	 * could be useful

	 */

	set_fs(KERNEL_DS);

	DUMP_WRITE(current, sizeof(*current));

end_coredump:

	set_fs(fs);

	return has_dumped;

fs/binfmt_aout.c

+0 −4
Original line number Diff line number Diff line
@@ -134,10 +134,6 @@ static int aout_core_dump(struct coredump_params *cprm) 
		if (!dump_write(file, dump_start, dump_size))

			goto end_coredump;

	}

/* Finally dump the task struct.  Not be used by gdb, but could be useful */

	set_fs(KERNEL_DS);

	if (!dump_write(file, current, sizeof(*current)))

		goto end_coredump;

end_coredump:

	set_fs(fs);

	return has_dumped;

include/linux/coredump.h

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
 */

static inline int dump_write(struct file *file, const void *addr, int nr)

{

	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;

	return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;

}



static inline int dump_seek(struct file *file, loff_t off)

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